Traffic channelizers are traffic control devices presenting a formidable object to warn an operator of a motor vehicle of a hazard located on the nontraffic side of the channelizer and thereby signal to the motor vehicle operator that he should not proceed into the area beyond the traffic channelizing devices because of the hazard. Such traffic channelizers usually are approximately 36 inches in height and 18 inches wide to function as a formidable target to gain the attention of the motor vehicle operator. Metallic drums have been employed for this purpose. Traffic channelizing devices constructed of plastic to avoid the problems of metallic channelizing drums have been develooped and are in use. One such plastic channelizer that has been widely utilized is disclosed in U.S. Pat. No. 4,083,033 granted on Apr. 4, 1978 and entitled "Traffic Control Element". One of the embodiments disclosed in U.S. Pat. No. 4,083,033 is a two-piece channelizing element that may be readily assembled together in a stabilized condition for traffic channelization purposes and yet the two pieces may be readily separated upon receiving a substantial impact by a motor vehicle or the like, to minimize damage to the traffic control element. In addition to the two-piece, plastic channelizing devices, one-piece plastic devices are presently in use. Present day one-piece devices generally have solid bottoms for storing stabilizing means such as a sandbag. All of the aforementioned traffic channelizers are adapted to mount a hazard warning light adjacent to the top thereof and are further adapted to be stackable.
Some uses of the one-piece plastic channelizers of the prior art have found them to be more convenient in use than a two-piece breakaway device, since some of these devices are provided with an open top that permits the open top to be readily grasped by an individual and allows the channelizing device to be dragged along the ground to a new channelizing position. In addition, some traffic channelizing devices permit the devices to be stacked, with or without the ballast stored therein, without the need to separate the top portion from the base portion for stacking purposes.
Present day plastic channelizers have been subjected to impact testing to determine their response to a substantial impact from the standpoint of the amount of damage caused by the impact, and the amount of displacement of the channelizers from the point of impact. One advantage of a one-piece, ballasted, traffic control device that was determined by the testing is a one-piece traffic channelizing element comes to rest more predictably near its original channelizing position. It was also determined that the point of impact and whether the channelizer had warning lights mounted thereon effects the trajectory and amount of displacement of the device and ultimately the final resting place. These tests further verified that the utilization of one or more flat sides prevented the traffic control devices from rolling beyond the flat side once the energy of impact is dissipated. The disadvantage that was revealed by the aforementioned testing was that the single piece or non-breakaway type of channelizing device was damaged more extensively with each impact than a two-piece channelizing device. It was also determined that it was more probable that the one-piece device would get tangled with the impacting motor vehicle to a greater extent than the two-piece device and present a danger to the motor vehicle operator.